What Causes a Home AC System to Freeze?

September 30th, 2014 admin

If you’ve chosen your AC unit appropriately (i.e. selected the right size for your home and picked a modern, energy-efficient model), chances are good that you’ll enjoy a comfortable home interior all summer long without spending an arm and a leg on cooling costs. Unfortunately, this isn’t the only factor that determines whether or not your air conditioning system continues to function at peak performance levels. And if your system freezes, you could not only lose air flow and cool temperatures; you could also damage your unit so badly that it needs to be repaired or replaced, especially if you fail to address known issues. But how can you tell if your unit is frozen and what is causing the problem? Here are a few tips that can benefit every homeowner with an AC system.

One of the first signs that your AC unit is suffering from a frozen evaporator is frost or ice on the coils or other parts of your equipment. So if you suspect that this is the problem, you might want to remove the housing from your unit. Excessive condensation could also be a clue. But the bigger issue is figuring out what is causing your AC system to freeze so that you can address the problem and find a way to solve it before your home turns into a sweat lodge.

And there are several potential issues that could cause your AC system to freeze. Air flow problems are the most common, so you need to make sure that the air going into your system is not restricted. Start by checking the returns in your home. If they are blocked by large furniture or other items, your AC unit might not be getting the air it needs to function properly, resulting in condensation and freezing. Of course, the problem could also lie outside your home. If your interior returns are clear, check to see if dirt and debris is clogging your unit. Simply turn off the power, remove the housing (checking to see if the outer shell is dirty), and then look for debris in coils that could be causing problems.

You should also check your filters regularly, especially if they tend to become laden with dirt and debris between your annual inspections. You should be able to clean or change them on your own without too much trouble, and it can help your system to remain clean and functional. Don’t forget that the vents in your home can also play a role in whether or not your system freezes. So before you start shutting them to funnel air to specific rooms, talk to your HVAC technician about the effect this can have on your system and how you can balance the air flow with dampers instead to preserve system function. You might also look into a single room AC unit if you just can’t seem to get cool air to the location where it is needed most.

Of course, your AC unit might suffer from other problems that lead to freezing, including a refrigerant leak or damaged parts. In this case, you’ll need professional help to diagnose and solve your particular issues. When problems arise, simply contact your HVAC technician for an emergency service call. The longer you wait, the worse the problem could get, causing damage to other parts of the system and increasing your costs.